Online retailer currently commands roughly 43 cents of every dollar spent online, according to analyst estimates

Amazon.com Inc. on Thursday delivered a double punch, reporting its best revenue growth in more than six years while topping $1 billion in profit for the second straight quarter.

The results surprised investors who were already expecting Amazon to post strong numbers as it extends its dominance in online retailing and builds on gains in cloud-computing services. But this quarter, Amazon was expected to post a more modest profit as it refocused on longer-term investments after a blowout holiday period.

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